Paracetamol Molecules Research Articles

Paracetamol Inclusion in Mechanically Interlocked Nanocages.

The solid-state synthesis and fast crystallization under kinetic control of poly-[n]-catenanes self-assembled of mechanically interlocked metal organic cages (MOCs) is virtually unexplored. This is in part, due to the lack of suitable crystals for single crystal X-ray diffraction (SC-XRD) analysis which limits their progress as advanced functional materials. Here we report the unprecedented inclusion of paracetamol in the cavities of amorphous materials constituted of M12L8, interlocked MOCs synthesized by mechanochemistry under kinetic control. Full structure determination of a low-crystallinity and low-resolution powders of the M12L8 poly-[n]-catenane including paracetamol has been carried out combining XRD data and Density Functional Theory (DFT) calculations using a multi-step approach. Each M12L8 cage contains six paracetamol guests which is confirmed by thermal analysis and NMR spectroscopy. The paracetamol loading has been also carried out by the instant synthesis method using a saturated paracetamol solution in which TPB and ZnI2 self-assemble immediately (i. e., 1-5 seconds) encapsulating ~7 paracetamol molecules in the M12L8 nanocages under kinetic control also giving a good selectivity. Benzaldehyde has been included in the M12L8 cages using amorphous M12L8 polycatenanes showing that the icosahedral cages can serve as potential nanoreactors for instance to study Henry reactions in the solid-state.

Triboelectric Charging Properties of the Functional Groups of Common Pharmaceutical Materials Using Density Functional Theory Calculations.

Triboelectrification is a ubiquitous and poorly understood phenomenon in powder processing, particularly for pharmaceutical powders. Charged particles can adhere to vessel walls, causing sheeting; they can also cause agglomeration, threatening the stability of powder formulations, and in extreme cases electrostatic discharges, which present a serious fire and explosion hazard. Triboelectrification is highly sensitive to environmental and material conditions, which makes it very difficult to compare experimental results from different publications. In this work, density functional theory (DFT) is used to investigate the charge transfer characteristics of several functional groups of paracetamol in order to better understand the mechanisms of charging at the nanoscale and the influence of the environmental and material properties on charge transfer. This is achieved by studying the structure and electronic properties at the molecule-substrate interface. Using this molecule-substrate approach, the charging contributions of individual functional groups are explored by examining the Hirschfeld charges, the charge density difference between the molecule and substrate, the density of states, and the location of the frontier orbitals (HOMO and LUMO) of a paracetamol molecule. Charge density difference calculations indicate a significant transfer of charge from the molecule to the surface. Observable regions of electron density enrichment and depletion are evident around the electron-donating and -withdrawing groups, respectively. The density of states for the paracetamol molecule evolves as it approaches the surface, and the band gap disappears upon contact with the substrate. Hirshfeld charge analysis reveals asymmetry in the charge redistribution around the molecule, highlighting the varying charging tendencies of different atoms.

Fabrication of cost-effective green assisted synthesis of MoO 3 NPs: its photocatalytic activity and electrochemical sensing actions on lead, mercury, and paracetamol molecules

Fabrication of cost-effective green assisted synthesis of MoO ₃ NPs: its photocatalytic activity and electrochemical sensing actions on lead, mercury, and paracetamol molecules

An on-site and portable electrochemical sensing platform based on spinel zinc ferrite nanoparticles for the quality control of paracetamol in pharmaceutical samples.

In this study, crystalline spinel zinc ferrite nanoparticles (ZnFe2O4 NPs) were successfully prepared and proposed as a high-performance electrode material for the construction of an electrochemical sensing platform for the detection of paracetamol (PCM). By modifying a screen-printed carbon electrode (SPE) with ZnFe2O4 NPs, the electrochemical characteristics of the ZnFe2O4/SPE and the electrochemical oxidation of PCM were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), chronoamperometry (CA), and differential pulse voltammetry (DPV) methods. The calculated electrochemical kinetic parameters from these techniques including electrochemically active surface area (ECSA), peak-to-peak separation (ΔEp), charge transfer resistance (Rct), standard heterogeneous electron-transfer rate constants (k0), electron transfer coefficient (α), catalytic rate constant (kcat), adsorption capacity (Γ), and diffusion coefficient (D) proved that the as-synthesized ZnFe2O4 NPs have rapid electron/mass transfer characteristics, intrinsic electrocatalytic activity, and facilitate the adsorption-diffusion of PCM molecules towards the modified electrode surface. As expected, the ZnFe2O4/SPE offered excellent analytical performance towards sensing of PCM with a detection limit of 0.29 μM, a wide linear range of 0.5-400 μM, and high electrochemical sensitivity of 1.1 μA μM-1 cm-2. Moreover, the proposed ZnFe2O4-based electrochemical nanosensor also exhibited good repeatability, high anti-interference ability, and practical feasibility toward PCM sensing in a pharmaceutical tablet. Based on these observations, the designed electrochemical platform not only provides a high-performance nanosensor for the rapid and highly efficient detection of PCM but also opens a new avenue for routine quality control analysis of pharmaceutical formulations.

Analysis of friction ridge evidence for trace amounts of paracetamol in various pharmaceutical industries by Raman spectroscopy.

The detection of potentially harmful substances presents a multifaceted challenge. On one hand, it can directly save lives, on the other, it can significantly aid and enhance police work, thereby increasing the effectiveness of investigations. The research conducted in this study primarily aims to identify paracetamol in fingerprints, considering situations involving direct contact of a person with paracetamol either chronically or in a single dose. The identification procedure presented, utilizing Raman spectroscopy, aims to rapidly detect the xenobiotic following ingestion by an individual, which involves touching the tablet with their fingers-this can be termed as touch evidence in forensic science investigations. Additionally, the authors focus on assessing the impact of additives present in drugs containing paracetamol as the main active ingredient. The screening results obtained will enable us to analyze the composition of drugs in terms of potentially toxic substances, and their influence on the physicochemical activity of the active substance. We successfully identified the paracetamol molecule using a noninvasive forensic trace detection method. Samples in the form of common drugs containing 500 mg of paracetamol were studied. Throughout the study, comprehensive validation of the method was ensured through the utilization of a statistical model, which excluded sensitivity to the presence of other substances, whether additives or from the external environment. The proposed approach to trace the content of substances in fingerprint using Raman scattering analysis provides a useful starting point to enhance current analytical methods not only in forensic science but also in toxicology.

Adsorption of pharmaceutical pollutants on activated carbon: Physicochemical assessment of the adsorption mechanism via advanced modelling

In this work, the adsorption mechanism of two pharmaceutical pollutants, paracetamol (PCM) and nimesulide (NMS), on activated carbon (AC) is elucidated via advanced modelling. Adsorption isotherms of PCM and NMS on a selected AC are obtained in the temperature range of 298–328 K. A physical model is applied to the experimental data set, assuming that the PCM and NMS molecules formed two layers on the AC, through the contribution of two adsorption energies. This theoretical analysis shows that the saturation adsorption capacities decrease with temperature from 259.27 to 211.82 mg/g for NMS and from 114.79 to 73.49 mg/g for PCM. This trend indicates that the tested AC has higher performances in removing NMS than PCM. The analysis of model parameters indicates that the number of molecules bound per active site (n) for the NMS-AC system are greater than unity for all the investigated temperatures, while it results to be equal to unity for PCM-AC system. This result allows concluding that an aggregation occurs during the adsorption of both the compounds, which are removed via interactions with one AC functional group. Different adsorption energies are determined, showing that the adsorption of NMS and PCM occurs via physisorption. Overall, this paper reports new theoretical assessments of PCM and NMS adsorption mechanism onto activated carbon via the adopted statistical physics model.

Highly dispersed gold nanoparticles anchoring on COFTAPB-DMTP for electrochemical detection of paracetamol

Small size Au nanoparticles (AuNPs) have aroused wide interest in electrochemical sensing due to its high surface atom utilization and superior electrical conductivity. However, there was a great challenge to balance the stability and small-size of AuNPs because of their large specific surface and high surface energy. Regarding this issue, herein, COFTAPB-DMTP was proposed as guiding support substrate for the synthesis of highly dispersed and small size AuNPs, where the uniform functional sites such N, O atoms on COFTAPB-DMTP could act as anchor points to induce in-situ reduction of AuNPs, and the confinement effects from the nanopore of COFTAPB-DMTP could limit their size. Then, an electrochemical paracetamol (PA) sensor was designed based on AuNPs@COFTAPB-DMTP since the abundant active centers and outstanding electrical conductivity of highly dispersed small size AuNPs conferred the composite excellent sensing performance. Moreover, the large specific surface, ordered pore channels and abundant heteroatomic functional groups of COFTAPB-DMTP could achieve high enrichment capacity toward PA molecules on electrode surface through pore effect, hydrogen bonding and electrostatic interaction. Benefiting from the combination between AuNPs and COFTAPB-DMTP, the AuNPs@COFTAPB-DMTP based sensor presents excellent analytical performance in term of low limit of detection (22 nM), satisfactory stability, reproducibility and selectivity. It indicated that COFs can be used as promising inducible substrate material for the preparation of highly dispersed and small size metal nanoparticles.

Exploration of DFT and TD-DFT computation to investigate the interaction between paracetamol and lithium or its compounds

Paracetamol is a commonly used antipyretic drug and its consumption drastically was increased during the COVID-19 times as fever was one of the symptoms. The excessive usage of paracetamol could harm humans, as the unused accumulated paracetamol can involve in the reaction with many small molecules as well as can interact with several biomolecules. Lithium chloride in its hydrated form is used as an antimanic drug and a geroprotector. It is needed in very small quantities by humans. Tetrahydrated form of lithium ion is the most stable hydrated form. Herein, the authors have investigated the interaction of paracetamol with tetrahydrated lithium chloride (1:1 and 1:2) using the DFT and TD-DFT calculations at 298 K and 310 K. The interaction of paracetamol with lithium chloride P1 (1:1), P2 (2:1), P3 (3:1) and P4 (4:1) are also studied by DFT calculations in default and CPCM model. The authors have calculated the free energy, optimization energy, dipole moment and other thermodynamic parameters of all the systems. Based on enthalpy and change in Gibbs free energy, the interaction was maximum between the paracetamol and tetrahydrated lithium chloride at 298 K as well as 310 K which indicates that the hydrated lithium chloride is being consumed by unused paracetamol. In P1 and P3, lithium showed interaction with oxygen of phenolic group and other atoms of all the paracetamol molecules present, while in P2 and P4, lithium showed these interactions with only one paracetamol molecule.

Elimination of aspirin and paracetamol from aqueous media using Fe/N-CNT/β-cyclodextrin nanocomposite polymers: theoretical comparative survey via advanced physical models.

The main purpose of this research is to theoretically investigate the adsorption of two pharmaceutical molecules, i.e. aspirin and paracetamol, using two composite adsorbents, i.e. N-CNT/β-CD and Fe/N-CNT/β-CD nanocomposite polymers. A multilayer model developed by statistical physics is implemented to explain the experimental adsorption isotherms at the molecular scale, so as to overpass some limitations of the classical adsorption models. The modelling results indicate that the adsorption of these molecules is almost accomplished by the formation of 3 to 5 adsorbate layers, depending on the operating temperature. A general survey of the number of adsorbate molecules captured by the adsorption site (npm) suggested that the adsorption process of pharmaceutical pollutants is multimolecular and that each adsorption site can capture several molecules simultaneously. Furthermore, the npm values demonstrated the presence of aggregation phenomena of aspirin and paracetamol molecules during adsorption. The evolution of the adsorbed quantity at saturation confirmed that the presence of Fe in the adsorbent enhanced the removal performance of the investigated pharmaceutical molecules. In addition, the adsorption of the pharmaceutical molecules aspirin and paracetamol on the N-CNT/β-CD and Fe/N-CNT/β-CD nanocomposite polymer surface involved weak physical type interactions, since the interaction energies do not overcome the threshold of 25 000 J mol-1.

Paracetamol removal from water using N-doped activated carbon derived from coconut shell: Kinetics, equilibrium, cost analysis, heat contributions, and molecular-level insight

Activated carbon (AC) and char derived from coconut shell were modified using urea and KOH to achieve N-doped AC. The effect of activated temperature and gas agent was studied. The series of adsorbents was characterized and it was found that the pore size and surface functional group were developed thoroughly. Paracetamol (PC) removal from aqueous solution was accomplished by adsorption in a batch system at 298 K. The intraparticle diffusion model was suitable to describe the kinetic PC removal from water rather than other models because of a complicated adsorption process in the pore connection of actual materials. The maximum capacity of these adsorbents was in a range of 39.9–357.1 mg/g, promoting them as an alternative adsorbent. Among them, the N-doped AC had the highest surface area (538 m2/g) and the highest PC adsorption capacity. The PC equilibrium uptakes in these samples were not pH-dependent, indicating that the pore size is the most dominant factor than the electrostatic charge of functional group on the solid surface for adsorption, which is evidenced in our simulation results. Furthermore, a Grand Canonical Monte Carlo simulation was used to study equilibrium adsorption. The effect of pore size and functional group type (carboxylic, hydroxyl, carbonyl, quaternary-N, pyrrolic-N, and pyridinic-N) were investigated on PC-water mixtures at 298 K. The heat contributions including fluid-fluid, fluid-solid, and fluid-functional group interactions of each adsorbate were investigated. The maximum capacity was found in the pore size of 0.70 nm, which was the best fit for complete monolayer coverage of PC molecules. The simulation confirmed that N-group types, especially pyridinic-N were more attractive than O-group types for enhanced PC removal. This work provided a new strategy to develop the optimal pore size and functional group type of ACs for high capacity of PC removal from aqueous solution. The estimated costs of production for char, AC, and N-doped AC were about 0.73, 2.63, and 3.83 U.S.$/kg respectively, indicating a highly competitive cost in the market. However, the N-doped AC was the cheapest price in order to remove the same amount of PC from aqueous solution.

Al/Cu-PILC as a Photo-Fenton Catalyst: Paracetamol Mineralization.

Pillared clays have shown to effectively catalyze the photo-Fenton process without the necessity of acidic conditions, which is a very attractive feature from the perspective of environmentally friendly processes, especially when high natural abundance of chemical elements are incorporated. In this work, the catalytic activity of Al/Cu interlayered pillared clays for the degradation and mineralization of paracetamol through a photo-Fenton-like process was investigated. Al/Cu-pillared clays were prepared by adding ane Al/Cu pillaring solution to a bentonite suspension. X-ray diffraction (XRD) confirmed the enlargement of the interlayer space of the clay provoked by the pillaring process and Al and Cu species in the prepared samples were verified by atomic absorption spectroscopy (AAS). The specific surface area of pure bentonite was 2-fold increased after the Al/Cu pillaring process. A synthetic paracetamol solution with an initial concentration of 100 ppm was prepared for the assessment of the activity of the prepared materials. Different catalyst concentrations were tested (0.2, 0.5, 0.75, and 1 g L–1) and the complete removal of paracetamol was achieved in all cases, but the highest mineralization rate (69.8 mg total organic carbon (TOC) gcat–1 h–1) corresponds to the catalyst loading of 0.5 g L–1. An ultraviolet-C (UVC) light source was employed, and no adjustment of the pH to acidic conditions was needed to achieve these results. Liquid chromatography coupled to mass spectroscopy (LC-MS) was employed to identify the reaction intermediates of paracetamol degradation. A proposed pathway for the oxidation of paracetamol molecule is presented. The effect of Cu content in the pillared clay and the stability and reusability of the catalyst were also assessed. The kinetic constants of paracetamol removal were 0.2318 and 0.0698 min–1, under photo-Fenton and UV + H2O2 processes, respectively.

Removal of Drug Pollutants from Aqueous Media Using Clam Shells Waste

The pharmaceutical products represent a serious environmental issue in the municipal wastewaters and waste water treatment plants (WWTP). Due to their resistance to biological degradation, the elimination of these pollutants is difficult. In the last years, paracetamol has been detected in higher concentrations in wastewaters. In order to avoid disturbing the aquatic life, economically viable procedures should be identified for removing these types of pollutants. In this context, the present paper has evaluated the efficiency of clam shells waste for retaining paracetamol molecules dispersed in aqueous solutions. The obtained results showed that high removal efficiency is obtained for 60 minutes adsorption duration and a ratio of about 1:100 clam shells: aqueous solution.

Voltammetric Determination of Paracetamol with Carbon Paste Electrode Modified with Molecularly Imprinted Electropolymer

Paracetamol is a commom analgesic and antipyretic drug which used for reliefing fever and head ache. The determination of paracetamol dose in pharmaceuticals is very important, becauce an overdose can cause fulminating hepatic necrosis and other toxic effects. Therefore, it is necessary to measure the dose of paracetamol for the patient with precision to avoid harm. Many analytical methodologies have been proposed for determination of paracetamol dose. One of the methods was developed in the past two decades. Generally, electroanalytical approach especially voltammetry method is particularly design for determination of paracetamol dose especially in modifying electrode. This study aims to modified carbon paste electrode with molecularly imprinted polymer (MIP). Significant advantages of using MIP are the superior stability, low cost and ease of preparation. The poly (3-aminiophenol) film was prepared by cyclic voltammetry method and 3-aminophenol monomer in supporting electrolyte (HClO4) with and whitout presence of paracetamol molecule. The effect of paracetamol was seen at cyclic voltammogram was founded, where oxidation peak potential of poly (3-aminophenol) shifted to more cathodic potentials from 0.948 to 0.780 V, in presence of paracetamol. The Ipa showed a good linear relationship with concentration in the range 0.01–0.1 mM, and the detection limit was 4,63 μM.

Molecular simulation of the paracetamol drug interaction with Pt-decorated BC3 graphene-like nanosheet

ABSTRACT Despite the important role of paracetamol (PC) in treating cough, fever, and pain, it may cause some serious side effects. Thus, its determination in biological samples is of great importance. Here, by employing density functional theory, the potential application of a pristine and a Pt-decorated BC3 nanosheet (Pt@BC3N) was studied in the detection of this drug. The PC molecule had a weak interaction with the pristine BC3N and the adsorption energy (Ead) was –9.3 kcal/mol. The sensing response of BC3N to PC was very small (∼9.7 at 298 K). A Pt atom preferentially tends to be adsorbed onto a B2C4 ring of BC3N with Ead of –52.3 kcal/mol. After Pt-decoration, PC had an interaction with the Pt atom, forming an η6-Pt half-sandwich structure with Ead of −35.1 kcal/mol, which indicates a strong chemisorption process. The sensing response of BC3N was amplified to 341.6 after Pt-decoration to a large extent because of a great charge transfer from PC to BC3N. A short recovery time of 2.09 s was obtained for the desorption of PC from the Pt@BC3N surface. The water solvent decreases Ead of PC and the sensing response of the Pt@BC3N to −28.3 kcal/mol and 270.3, respectively.

Kinetic control concept for the diffusion processes of paracetamol active molecules across affinity polymer membranes from acidic solutions

BackgroundParacetamol compound remains the most used pharmaceutical as an analgesic and antipyretic for pain and fever, often identified in aquatic environments. The elimination of this compound from wastewater is one of the critical operations carried out by advanced industries. Our work objective was to assess studies based on membrane processes by using two membranes, polymer inclusion membrane and grafted polymer membrane containing gluconic acid as an extractive agent for extracting and recovering paracetamol compound from aqueous solutions.ResultThe elaborated membrane characterizations were assessed using Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Kinetic and thermodynamic models have been applied to determine the values of macroscopic (P and J0), microscopic (D* and Kass), activation and thermodynamic parameters (Ea, ΔH#, ΔS#, ΔH#diss, and ΔH#th). All results showed that the PVA–GA was more performant than its counterpart GPM–GA, with apparent diffusion coefficient values (107D*) of 41.807 and 31.211 cm2 s−1 respectively, at T = 308 K. In addition, the extraction process for these membranes was more efficient at pH = 1. The relatively low values of activation energy (Ea), activation association enthalpy (ΔH≠ass), and activation dissociation enthalpy (ΔH≠diss) have indicated a kinetic control for the oriented processes studied across the adopted membranes much more than the energetic counterpart.ConclusionThe results presented for the quantification of oriented membrane process ensured clean, sustainable, and environmentally friendly methods for the extraction and recovery of paracetamol molecule as a high-value substance.

Broadband dielectric relaxation spectroscopy and molecular dynamics simulation study of paracetamol-propylene glycol solutions

The complex permittivity ε*(ω) = ε′(ω) - ε“(ω) was studied for a series of paracetamol (PCM) – propylene glycol (PG) solutions over the broadband frequency range of 20 Hz to 20 GHz at different temperatures ranging from 293.15 K to 323.15 K. Measurements of the complex permittivity were carried out using Agilent Precision LCR meter E4980A with Agilent 16452A liquid test fixture (for 20 Hz to 2 MHz frequency region) and Anritsu Shockline Vector Network Analyser MS46322A with DAK-3.5 probe (for 200 MHz to 20 GHz frequency region). Obtained broadband frequency dependent dielectric data were analyzed to explore the interaction mechanisms and structural behavior of PCM and PG molecules in mixed state in terms of molar PCM concentration and temperature variation. Temperature dependent dc conductivity response of all solutions exhibited Arrhenius behavior from which activation energy was calculated. Microwave complex permittivity data were fitted to the Cole-Davidson model in order to determine dipolar relaxation parameters of the solutions. Dielectric constant and dielectric loss values at a spot frequency of 2.45 GHz were utilized to determine the microwave heating parameters and analyzed in view of its suitability for the microwave dielectric heating in pharmaceuticals. Molecular dynamics simulation study for selected concentrations of PCM in PG was also conducted in order to understand the actual mechanism of H-bonding interactions in the solutions and to justify the inferences derived from the experimental results.

Insight into plasma degradation of paracetamol in water using a reactive molecular dynamics approach

Plasma-produced reactive oxygen and nitrogen species are expected to promote micropollutant degradation in water and more generally in liquids. Among these species, the hydroxyl radical (HO•) is recognized as being the most efficient. Molecular dynamics simulations were carried out to determine the reaction steps of HO• interaction with the paracetamol molecule in water, a pharmaceutical residue that is frequently detected in surface and tap water and is well documented. Calculations were performed at various temperatures to determine the oxidation pathways, and the intermediate and final products were identified. Assuming a ratio of 10% HO• in water, it was found that a local temperature of 2500 K is required to decompose paracetamol to CO, H2O, NH3, and C2H2.

Adsorption mechanisms of single and simultaneous removal of pharmaceutical compounds onto activated carbon: Isotherm and thermodynamic modeling

The simultaneous adsorption of pharmaceutical compounds is a challenge for real-life water treatment applications. Therefore, the present study aimed to investigate the simultaneous adsorption of paracetamol and nimesulide, using activated carbon (AC) as an adsorbent. Single adsorption experiments were also performed to compare the adsorption behavior changes. For instance, AC showed a higher single adsorption capacity for nimesulide (196.32 mg g−1) than paracetamol (58.21 mg g−1). Interestingly, during the binary adsorption, nimesulide molecules were adsorbed on active sites previously occupied by paracetamol molecules. This displacement phenomenon, due to the competition of pharmaceutical molecules at higher pharmaceutical concentrations, promoted the adsorption of nimesulide (199.49 mg g−1) and strongly suppressed the adsorption of paracetamol (25.80 mg g−1) on AC. The greater affinity between the AC and nimesulide was related to the more hydrophobic nature of nimesulide (log Kow = 2.60) than that of paracetamol (log Kow = 0.49). Besides, FTIR spectra, before and after adsorption, suggested that paracetamol was adsorbed only by H–bonding interactions, while nimesulide was adsorbed by H–bonding, π−π, and n−π dispersion interactions. Langmuir model (R2 ≥ 0.991) successfully adjusted the single equilibrium isotherms for both pharmaceuticals. Whereas, Extended Langmuir model (R2 ≥ 0.984) was chosen to predict the binary adsorption of paracetamol and nimesulide on AC. Finally, the thermodynamic analysis suggested exothermic, favorable, and spontaneous adsorption, with low adsorption energies that supported the physisorption.

Effect of Choice of Solvent on Crystallization Pathway of Paracetamol: An Experimental and Theoretical Case Study

The choice of solvents influences crystalline solid formed during the crystallization of active pharmaceutical ingredients (API). The underlying effects are not always well understood because of the complexity of the systems. Theoretical models are often insufficient to describe this phenomenon. In this study, the crystallization behavior of the model drug paracetamol in different solvents was studied based on experimental and molecular dynamics data. The crystallization process was followed in situ using time-resolved Raman spectroscopy. Molecular dynamics with simulated annealing algorithm was used for an atomistic understanding of the underlying processes. The experimental and theoretical data indicate that paracetamol molecules adopt a particular geometry in a given solvent predefining the crystallization of certain polymorphs.

Forecasting the multicomponent adsorption of nimesulide and paracetamol through artificial neural network

The multicomponent adsorption modeling is a challenge since the prediction of the interactions between the adsorbates is hard. An alternative is the use of models based on artificial intelligence. This study evaluated the single and binary adsorption of nimesulide and paracetamol on activated carbon (AC) using an artificial neural network (ANN). The characterization revealed a typical AC with a specific surface area reaching 866.12 m2 g−1 and point of zero charge (pHPZC) of 6.50. The adsorption capacity for each pharmaceutical compound was investigated as a function of adsorbent particle size, adsorbent dosage, contact time, and initial concentration. Experimental results indicated that nimesulide presented a higher affinity for the active sites of the AC than paracetamol, which can be attributed to hydrophobic and π−π dispersion interactions between nimesulide and AC. During the binary adsorption, nimesulide molecules competed with paracetamol molecules, suppressing the adsorption of paracetamol. The highest adsorption capacities were found for the adsorbent dosage of 0.5 g L−1 and particle size of 150 μm, in which the AC removed 98% of nimesulide and 76% of paracetamol in 300 min. An optimal ANN trained by the Bayesian regularization backpropagation algorithm and structured with three hidden layers with five neurons was successfully developed to simultaneously predict the single and binary adsorption of nimesulide (R = 0.9989) and paracetamol (R = 0.9985).